dealing the cards online

When playing a hand online, for example after the flop, are the cards remaining in the deck set or are they continually being electronically shuffled prior to being dealt?

Weel thats an actually an interesting question, never though about that.
But from my limited knowledge of RNG which is mostly java.util.random I would guess that there is no shuffling involved at all, you just got random card from the deck then another random card from the remaining part of the deck then same goes with flop turn and the river. Tho it could be setup to shuffle the deck before and make it an array before the hand starts.
Whatever it is, it wont change anything from player's perspective imo, its just a system solution what to use...

I would think a card is randomly selected as it is needed, and a new set is made from the remaining cards. If a next card is needed, then it will be randomly selected from this new set... and so on.

The objective is for the program to be as efficient as possible, and determining the whole deck pre deal is ineffective, as would be a constant shuffle.

I think that all the letters are randomly distributed, although to be honest I don't have any knowledge and information regarding this topic, I will be attentive to this thread to learn more about this topic since it looks very interesting